JPH06328352A - Compound working machine - Google Patents

Abstract

PURPOSE:To machine material extending from metal material to brittle material with decrease in a process affected layer and maintaining fine form accuracy. CONSTITUTION:A work 11 is rotated by a work spindle 13, and machining liquid 21a having low concentration ia supplied to its surface through a machining liquid nozzle 21. A short wave length laser 18a having width equivalent to the radius of the work 11 is irradiated to the surface of the work 11 supplied with the machining liquid 21a by a laser generator 17 and a laser optical system 18 to generate reaction product. A cup grinding wheel 15 is rotated by a grinding wheel shaft 16, which is moved in a direction shown by an arrow (f) by a movable table 19 and a table driving motor 20 at speed fitted to the growing speed of the reaction product to press the cup grind stone onto the surface of the work 11 for grinding the reaction product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound machine, and more particularly to a compound machine using a laser.

[0002]

2. Description of the Related Art Conventionally, there have been known some methods for grinding or polishing the surface of a work such as a semiconductor wafer. For example, a grinding method is known in which etching with a high-concentration alkaline aqueous solution and high-power laser is used in combination with grinding with a grindstone.

In this grinding method, the work is first dipped or applied in a high-concentration alkaline aqueous solution, for example, a 10% sodium hydroxide solution. Then, by irradiating the work surface with a high-power (for example, 300 W) laser to raise the temperature of the work surface, a large amount of dissolving action by etching is caused on the work surface by a chemical reaction with an alkaline aqueous solution, and The modified layer on the surface of the work produced by the chemical reaction is ground by a grindstone together with the deeper base material. This method reduces the processing load, so
It is performed for the purpose of reducing the wear of the diamond grindstone and grinding with high efficiency.

As another example, mechanochemical polishing is known. In this method, first, the work is immersed in an alkaline aqueous solution in which loose abrasive grains are dispersed, for example, a potassium hydroxide solution. At this time, the work and the aqueous solution are heated to 40 to 60 degrees so that a chemical reaction easily occurs, and a reaction film such as a hydrated film is formed on the surface of the work. Then, the reaction film is removed by polishing the work surface with a viscoelastic body such as polyurethane.

A method called so-called electrolytic composite polishing is also known. In this method, the work is immersed in an electrolytic solution in which loose abrasive grains are dispersed, and the work is used as an anode, so that electrolysis is caused between the work and the electrode used as a cathode. Then, the non-conductive film generated on the surface of the work by electrolysis during the electrolysis is removed by polishing with a viscoelastic body such as polyurethane.

[0006]

However, each of the conventional methods has the following problems. That is, in the grinding method that uses both etching and grinding, the working liquid used is a dangerous substance such as a high-concentration alkaline solution.
It is difficult to handle, and it is necessary to apply anticorrosion treatment to the processing machine. Further, since a special processing device for drainage processing is required, the processing machine becomes expensive.

Further, etching with a high-power laser and a high-concentration alkaline solution reduces the processing load because the products generated by the dissolution action of a large amount of work and the chemical reaction with the work become softer than the work base material. Has an aim. In this processing method, etching is the main component, and the work surface is rough, so that the work surface becomes rough. Therefore, in order to improve the surface roughness of the work, machining with a grindstone is performed as a final finish. However, when the final finishing process is machining, especially when the work is a brittle material, a work-affected layer such as a crack remains on the work surface.

On the other hand, in mechanochemical polishing,
Since the work is processed while being heated, there is a problem that the work is deformed due to a temperature difference before and after the temperature becomes constant and before and after the work, and the shape accuracy is deteriorated. Further, in the electrolytic composite polishing, since electrolysis is used, there is a problem that the work can be processed only when the work is a conductive substance such as metal.

Therefore, an object of the present invention is to perform processing from a metal to a brittle material with good shape accuracy and with a small number of work-affected layers, without requiring special drainage treatment of the working liquid. It is to provide a compound processing machine.

[0010]

According to a first aspect of the invention, a holding means for holding a work, a working liquid supply means for supplying a low concentration working liquid to the work surface, and a short wavelength laser on the work surface. And a surface processing means for processing the reaction product generated on the surface of the work by irradiation of the short-wavelength laser in accordance with the growth rate of the product. To achieve.

[0011]

In the combined processing machine according to the first aspect of the present invention, the processing liquid supply means supplies a low concentration processing liquid to the surface of the work held by the holding means, and the laser irradiation means irradiates the workpiece with a short wavelength laser. . As a result, reaction products are produced on the surface of the work. The surface processing means processes the reaction product in accordance with the product growth rate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the combined processing machine of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows a main configuration of a combined processing machine according to the first embodiment.

The multi-tasking machine of this embodiment comprises a chuck 12 for adsorbing and fixing a work 11 and a work spindle 13 for rotating the chuck 12 around a shaft a as shown by an arrow b by a drive motor (not shown). I have it. The work spindle 13 is fixed to the support base 14 by a fixing member (not shown).

Further, the multi-tasking machine is provided with a cup grindstone 15 for grinding the workpiece 11. The cup grindstone 1
5 is rotated by a grindstone shaft 16 about an axis d as indicated by an arrow e. In this embodiment, the cup grindstone 15 has high rigidity. The grindstone shaft 16 and the work spindle 13 described above have known structures.

A laser oscillator 17 is provided to the right of the grindstone shaft 16.
And a laser optical system 18 are provided. The laser oscillator 17 outputs a short-wavelength laser of about several watts, and is, for example, an excimer laser or a several-order (third-order or fourth-order laser).
Next) A harmonic YAG laser or the like is used. Laser optical system 1
Reference numeral 8 spreads the laser light output from the output portion 17a of the laser oscillator 17 to the radial width of the work 11 and irradiates the work 11 as indicated by 18a.

These laser oscillator 17 and laser optical system 1
8 and the grindstone shaft 16 are fixed to the moving table 19 by a fixing member (not shown). This moving table 19
Is installed so as to be movable in a direction (arrow f) perpendicular to the surface of the work 11 on a stable surface (not shown). The table drive motor 20 moves the moving table 19 at a speed of several microns or less per minute according to the control of a control system (not shown). The cup grindstone 15 is designed to cut into the work 11 by the movement of the moving table 19 by the table driving motor 20, and the cutting device of the present embodiment is constituted by the moving table 19, the table driving motor 20 and a control system (not shown). A is configured.

The cutting device A is used for the work spindle 1
It may be provided on the third side and the work 11 may be moved with respect to the cup grindstone 15. Also, the laser oscillator 1
At least one of 7 and the laser optical system 18 may be installed outside the moving table 19. A machining liquid nozzle 21 is arranged on the right side of the laser optical system 18 in the drawing, and the machining liquid 21a supplied from a supply device (not shown) is supplied to the workpiece 1.
It is designed to be immersed in the surface 1. As the processing liquid 21a, a low-concentration alkaline aqueous solution, for example, a potassium hydroxide solution having a concentration of 5% or less, or a chemical type grinding liquid is used.

Next, the operation of the first embodiment thus constructed will be described. First, motors (not shown) for the work spindle 13 and the grindstone shaft 16 are driven to rotate the work 11 and the cup grindstone 15. Then, the working liquid 21a is supplied to the working liquid nozzle 21, and the surface of the workpiece 11 is dipped in the working liquid 21a.

A laser oscillator 17 and a laser optical system 18 irradiate a short wavelength laser having a radius width of the work 11 on the surface soaked with the machining liquid 21a, and the temperature of the surface of the work 11 is locally increased in the depth direction. Raise to. This allows
The work 11 reacts with the working liquid 21a, and a reaction film such as a hydrated film or an oxide film is formed on the surface thereof.

Next, the table drive motor 20 is driven to move the moving table 19 in the direction indicated by the arrow f, and the cup grindstone 15 is brought into contact with and pressed against the surface of the work 11 to start grinding. However, the moving speed of the moving table 19 at this time is such that the table driving motor 20 is driven so that the cutting speed of the cup grindstone 15 into the work 11 becomes equal to the growth speed of reaction products (several microns or less per minute). Control.

As a result, only the reaction product produced on the surface of the work 11 is ground by the cup grindstone 15. Then, along with the rotation of the work 11, the generation of the reaction product by the laser and the grinding of the reaction product by the cup grindstone 15 are sequentially repeated to process the work 11.

Since the cup grindstone 15 having a high rigidity is used in this embodiment, the shape of the cup grindstone 15 should not be destroyed unlike the case of polishing with a viscoelastic body as in the conventional mechanochemical polishing or electrolytic composite machining. It is possible to process the work 11 without using it. FIG. 2 shows the main configuration of the multi-tasking machine according to the second embodiment. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be appropriately omitted.

In this embodiment, a high-rigidity cylindrical grindstone 22 is used as a grindstone for processing the work 11, and the outer peripheral surface of the cylindrical grindstone 22 contacts the surface of the work 11. The grindstone shaft 16 that rotates the cylindrical grindstone 22 is fixed to the reciprocating table 23. Reciprocating table 2
3 is movably installed on the guide table 24, and is reciprocated in a direction perpendicular to the paper surface in the figure by a drive motor (not shown) with the reciprocating table moving width set to (radius of work 11) ≦ (reciprocating table moving width). It is designed to move.

The laser oscillator 17, the laser optical system 18, and the machining liquid nozzle 21 are fixed by a fixing member (not shown) so as to maintain a constant position regardless of the reciprocal movement of the grindstone shaft 16. In addition, in this embodiment, the cutting device A is
The work spindle 13 is provided on the work spindle 13 side, whereby the work spindle 13 moves in the direction of the arrow g, and the cylindrical grindstone 22 is cut into the work 11. The cutting device A may be provided on the grindstone shaft 16 side as in the first embodiment. In this case, the moving table 19 includes the guide table 24, the laser oscillator 17, the laser optical system 18, and the like. Fixed.

Next, the operation of the second embodiment thus constructed will be described. First, the cylindrical grindstone 22 and the work 11 are respectively rotated by the grindstone shaft 16 and the work spindle 13, and the grindstone shaft 16 is reciprocated at a predetermined speed in a direction perpendicular to the paper surface.

Then, a low-concentration machining liquid 21a is supplied to the surface of the work 11 by the machining liquid nozzle 21, and a laser oscillator 17 and a laser optical system 18 are applied to the machining liquid 21a.
The reaction product is generated on the surface of the work 11 by irradiating a short wavelength laser having a radius width of 1. Next, the table drive motor 2
When the moving table 19 is moved in the direction of the arrow g by driving 0, and the cylindrical grindstone 22 is cut into the work 11 at the same speed as the growth rate of the reaction product as in the first embodiment,
The cylindrical grindstone 22 grinds the reaction product on the surface of the work 11 while reciprocating.

Although each embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention. For example, in each of the above embodiments, a grindstone having a high rigidity is used as the grindstone for processing the workpiece 11, but a viscoelastic grindstone may be used. Further, a viscoelastic pad such as polyurethane may be used instead of the grindstone, free abrasive grains may be dispersed in the working liquid, and the reaction product on the surface of the work 11 may be removed by polishing with the viscoelastic pad.

Instead of the cutting device A, for example, a cutting device which presses the grindstone against the surface of the work 11 with a constant pressure by an air cylinder, an oil cylinder or the like may be used. Further, instead of rotating the work 11, the laser oscillator 17, the grindstone shaft 16 or the like is used for the work 11
The entire surface of the workpiece 11 may be processed by moving the workpiece 11 with respect to the workpiece 11.

[0029]

As described above, according to the multi-tasking machine of the present invention, only the reaction product formed on the surface of the work by the low-concentration working liquid and the short wavelength laser is ground by the grindstone. In addition, it is possible to perform processing with little or no work-affected layer.

Further, since the temperature of the work is locally raised in the depth direction by using the short wavelength laser, the work is not deformed due to the temperature rise, and the work with high shape accuracy can be performed. Since a low-concentration processing liquid is used, drainage processing is easy, no special anticorrosion treatment is required for the processing machine, and the processing machine does not become expensive.

Further, since it is a composite processing using a laser, not only metal but also brittle material having no conductivity can be processed.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a main configuration of a combined processing machine according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view showing the main configuration of a combined processing machine according to a second embodiment of the present invention.

[Explanation of symbols]

 11 Work 12 Chuck 13 Work Spindle 15 Cup Grinding Stone 16 Grinding Stone Axis 17 Laser Oscillator 17a Output Unit 18 Laser Optical System 18a Laser Light 19 Moving Table 20 Table Driving Motor 21 Machining Liquid Nozzle 21a Machining Liquid 22 Cylindrical Grinding Stone 23 Reciprocating Table 24 Guide Table A notching device

Claims (1)

[Claims] 1. A holding means for holding a work, a working liquid supply means for supplying a low-concentration working liquid to the work surface, a laser irradiation means for irradiating the work surface with a short wavelength laser, and the short wavelength laser. And a surface processing means for processing the reaction product generated on the surface of the work by irradiation of the product according to the growth rate of the product.